The foregoing prior art teaches the employment of various means for blood transfusion or the transfusion of body fluids relative to a human patient. However, the various apparatus and methods do not provide for the concurrent removal and replacement of blood relative to a patient wherein the amount of blood being removed from the patient is almost exactly equal to the amount of blood being injected into the patient so that the patient is not upset in any way by any differential in the volumetric displacement of fluids relative to his body. Accordingly, the prior art lacks precise control of the removal of fluids from a patient's body relative to the precise replacement of the fluids on a volumetric equality basis.
Many of the prior art devices have alternating mechanism which alternately withdraws a small portion of blood from the patient and then subsequently replaces it and thus, such means may be cycled many times depending upon the amount of fluid or blood to be displaced and transfused.
This system however, does not permit the concurrent equality volumetrically of the displacement and transfusion of blood or other body fluids relative to a patient either into or out of a vein concurrently relative to the reciprocal displacement or transfusion in relation to an artery.